Study of smoke protection measures within high rise apartments

This thesis intends to develop an understanding of stair pressurisation systems in high-rise residential buildings, to provide information regarding the performance of such systems in a credible evacuation scenario. Stair pressurisation systems are designed to create a smoke-proof barrier, preventing the ingress of smoke into staircases within buildings over 25m tall. Currently, all stair pressurisation systems are designed with the same commissioning requirements in mind, regardless of other factors such as height or evacuation strategies. In tall buildings, evacuation strategies can utilise phased or simultaneous evaluation of of numerous storeys at once. Given that the number of doors open into a stair in a credible evacuation of a building exceeds the the number required to be open during system commissioning, it is possible that such a system may not perform as intended when it is required the most. This report examines the performance of a stair pressurisation with a differing number of doors open into the shaft in order to determine performance as the number of doors open at once increases. Simulations using FDS have shown that a system that would pass commissioning requirements allows smoke in the shaft if there are more than 4 doors open simultaneously, signifying the evacuation of three storeys simultaneously. Past this limit, the amount of smoke which leaks into the staircases continues to increase as more door open. Overall, the simulations conducted show a disconnect between the Australian legislation for the commissioning of smoke control systems and the evacuation methodology used in taller buildings, signifying a need to create an interface between the commissioning of systems and credible scenarios in an emergency.